aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/rcutree_trace.c
blob: c8e97853b970f71ad662732ef46da011cf46ac1d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
/*
 * Read-Copy Update tracing for classic implementation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright IBM Corporation, 2008
 *
 * Papers:  http://www.rdrop.com/users/paulmck/RCU
 *
 * For detailed explanation of Read-Copy Update mechanism see -
 *		Documentation/RCU
 *
 */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/rcupdate.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/atomic.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

#define RCU_TREE_NONCORE
#include "rcutree.h"

static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
{
	if (!rdp->beenonline)
		return;
	seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d",
		   rdp->cpu,
		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
		   rdp->completed, rdp->gpnum,
		   rdp->passed_quiesc, rdp->passed_quiesc_completed,
		   rdp->qs_pending);
#ifdef CONFIG_NO_HZ
	seq_printf(m, " dt=%d/%d dn=%d df=%lu",
		   rdp->dynticks->dynticks,
		   rdp->dynticks->dynticks_nesting,
		   rdp->dynticks->dynticks_nmi,
		   rdp->dynticks_fqs);
#endif /* #ifdef CONFIG_NO_HZ */
	seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
	seq_printf(m, " ql=%ld b=%ld", rdp->qlen, rdp->blimit);
	seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
		   rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
}

#define PRINT_RCU_DATA(name, func, m) \
	do { \
		int _p_r_d_i; \
		\
		for_each_possible_cpu(_p_r_d_i) \
			func(m, &per_cpu(name, _p_r_d_i)); \
	} while (0)

static int show_rcudata(struct seq_file *m, void *unused)
{
#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "rcu_preempt:\n");
	PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "rcu_sched:\n");
	PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
	seq_puts(m, "rcu_bh:\n");
	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
	return 0;
}

static int rcudata_open(struct inode *inode, struct file *file)
{
	return single_open(file, show_rcudata, NULL);
}

static const struct file_operations rcudata_fops = {
	.owner = THIS_MODULE,
	.open = rcudata_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
{
	if (!rdp->beenonline)
		return;
	seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
		   rdp->cpu,
		   cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
		   rdp->completed, rdp->gpnum,
		   rdp->passed_quiesc, rdp->passed_quiesc_completed,
		   rdp->qs_pending);
#ifdef CONFIG_NO_HZ
	seq_printf(m, ",%d,%d,%d,%lu",
		   rdp->dynticks->dynticks,
		   rdp->dynticks->dynticks_nesting,
		   rdp->dynticks->dynticks_nmi,
		   rdp->dynticks_fqs);
#endif /* #ifdef CONFIG_NO_HZ */
	seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
	seq_printf(m, ",%ld,%ld", rdp->qlen, rdp->blimit);
	seq_printf(m, ",%lu,%lu,%lu\n",
		   rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
}

static int show_rcudata_csv(struct seq_file *m, void *unused)
{
	seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
#ifdef CONFIG_NO_HZ
	seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
#endif /* #ifdef CONFIG_NO_HZ */
	seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n");
#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "\"rcu_preempt:\"\n");
	PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "\"rcu_sched:\"\n");
	PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
	seq_puts(m, "\"rcu_bh:\"\n");
	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
	return 0;
}

static int rcudata_csv_open(struct inode *inode, struct file *file)
{
	return single_open(file, show_rcudata_csv, NULL);
}

static const struct file_operations rcudata_csv_fops = {
	.owner = THIS_MODULE,
	.open = rcudata_csv_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
{
	unsigned long gpnum;
	int level = 0;
	int phase;
	struct rcu_node *rnp;

	gpnum = rsp->gpnum;
	seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
		      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
		   rsp->completed, gpnum, rsp->signaled,
		   (long)(rsp->jiffies_force_qs - jiffies),
		   (int)(jiffies & 0xffff),
		   rsp->n_force_qs, rsp->n_force_qs_ngp,
		   rsp->n_force_qs - rsp->n_force_qs_ngp,
		   rsp->n_force_qs_lh);
	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
		if (rnp->level != level) {
			seq_puts(m, "\n");
			level = rnp->level;
		}
		phase = gpnum & 0x1;
		seq_printf(m, "%lx/%lx %c%c>%c%c %d:%d ^%d    ",
			   rnp->qsmask, rnp->qsmaskinit,
			   "T."[list_empty(&rnp->blocked_tasks[phase])],
			   "E."[list_empty(&rnp->blocked_tasks[phase + 2])],
			   "T."[list_empty(&rnp->blocked_tasks[!phase])],
			   "E."[list_empty(&rnp->blocked_tasks[!phase + 2])],
			   rnp->grplo, rnp->grphi, rnp->grpnum);
	}
	seq_puts(m, "\n");
}

static int show_rcuhier(struct seq_file *m, void *unused)
{
#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "rcu_preempt:\n");
	print_one_rcu_state(m, &rcu_preempt_state);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "rcu_sched:\n");
	print_one_rcu_state(m, &rcu_sched_state);
	seq_puts(m, "rcu_bh:\n");
	print_one_rcu_state(m, &rcu_bh_state);
	return 0;
}

static int rcuhier_open(struct inode *inode, struct file *file)
{
	return single_open(file, show_rcuhier, NULL);
}

static const struct file_operations rcuhier_fops = {
	.owner = THIS_MODULE,
	.open = rcuhier_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static int show_rcugp(struct seq_file *m, void *unused)
{
#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_printf(m, "rcu_preempt: completed=%ld  gpnum=%lu\n",
		   rcu_preempt_state.completed, rcu_preempt_state.gpnum);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_printf(m, "rcu_sched: completed=%ld  gpnum=%lu\n",
		   rcu_sched_state.completed, rcu_sched_state.gpnum);
	seq_printf(m, "rcu_bh: completed=%ld  gpnum=%lu\n",
		   rcu_bh_state.completed, rcu_bh_state.gpnum);
	return 0;
}

static int rcugp_open(struct inode *inode, struct file *file)
{
	return single_open(file, show_rcugp, NULL);
}

static const struct file_operations rcugp_fops = {
	.owner = THIS_MODULE,
	.open = rcugp_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
{
	seq_printf(m, "%3d%cnp=%ld "
		   "qsp=%ld rpq=%ld cbr=%ld cng=%ld "
		   "gpc=%ld gps=%ld nf=%ld nn=%ld\n",
		   rdp->cpu,
		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
		   rdp->n_rcu_pending,
		   rdp->n_rp_qs_pending,
		   rdp->n_rp_report_qs,
		   rdp->n_rp_cb_ready,
		   rdp->n_rp_cpu_needs_gp,
		   rdp->n_rp_gp_completed,
		   rdp->n_rp_gp_started,
		   rdp->n_rp_need_fqs,
		   rdp->n_rp_need_nothing);
}

static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
{
	int cpu;
	struct rcu_data *rdp;

	for_each_possible_cpu(cpu) {
		rdp = per_cpu_ptr(rsp->rda, cpu);
		if (rdp->beenonline)
			print_one_rcu_pending(m, rdp);
	}
}

static int show_rcu_pending(struct seq_file *m, void *unused)
{
#ifdef CONFIG_TREE_PREEMPT_RCU
	seq_puts(m, "rcu_preempt:\n");
	print_rcu_pendings(m, &rcu_preempt_state);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
	seq_puts(m, "rcu_sched:\n");
	print_rcu_pendings(m, &rcu_sched_state);
	seq_puts(m, "rcu_bh:\n");
	print_rcu_pendings(m, &rcu_bh_state);
	return 0;
}

static int rcu_pending_open(struct inode *inode, struct file *file)
{
	return single_open(file, show_rcu_pending, NULL);
}

static const struct file_operations rcu_pending_fops = {
	.owner = THIS_MODULE,
	.open = rcu_pending_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static struct dentry *rcudir;

static int __init rcutree_trace_init(void)
{
	struct dentry *retval;

	rcudir = debugfs_create_dir("rcu", NULL);
	if (!rcudir)
		goto free_out;

	retval = debugfs_create_file("rcudata", 0444, rcudir,
						NULL, &rcudata_fops);
	if (!retval)
		goto free_out;

	retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
						NULL, &rcudata_csv_fops);
	if (!retval)
		goto free_out;

	retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
	if (!retval)
		goto free_out;

	retval = debugfs_create_file("rcuhier", 0444, rcudir,
						NULL, &rcuhier_fops);
	if (!retval)
		goto free_out;

	retval = debugfs_create_file("rcu_pending", 0444, rcudir,
						NULL, &rcu_pending_fops);
	if (!retval)
		goto free_out;
	return 0;
free_out:
	debugfs_remove_recursive(rcudir);
	return 1;
}

static void __exit rcutree_trace_cleanup(void)
{
	debugfs_remove_recursive(rcudir);
}


module_init(rcutree_trace_init);
module_exit(rcutree_trace_cleanup);

MODULE_AUTHOR("Paul E. McKenney");
MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
MODULE_LICENSE("GPL");